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You Asked: Muscle vs. Fat?

Dear Fit Sugar,
I'm on a mission to lose that last 10 pounds, which has been so difficult, and I'm training for a half-marathon as well. I eat well and exercise a lot — cardio almost every day and strength training five days a week. I've always heard that muscle weighs more than fat, but after I reached a plateau, I've found that I've been gaining weight. Not much, just a pound or two, but still gaining weight. How do we know when weight gained is added muscle mass, and when it means we need to reevaluate the calories we consume? I'm frustrated that all the hard work only turned into a weight gain.
—Confused and Frustrated

This is a common source of frustration and confusion, but I think I can help clear up a few questions. To see what I have to say about muscles and fat, just


Losing weight is not a simple task, and it is important to remember that it is not really pounds you want to lose, but fat. You want to lose fat and gain lean muscle tissue. People often say that muscle weighs more than fat, but that is a misstatement. Muscle is actually more dense than fat, so a pound of muscle takes up less space than fat. Another way to look at fat versus muscles is that a cubic inch of muscle will weigh more than a cubic inch of fat. Muscle is about 18 percent more dense than fat.

Using weight to determine the health of our bodies or our fitness level is not really accurate. What you want to measure is your body fat percentage, and you can do so with a scale designed for that purpose, or have it measured in a more expensive, but more accurate way. While you say you are gaining weight, I am wondering if your clothes are getting tight, which would be an indicator that you're gaining muscle and fat instead of just muscle. Sometimes something as simple as your jeans feeling tight can be the signal you need to fine-tune your weight-loss efforts.

When you hit a plateau, it is a good idea to look at both what you are eating and how you're exercising. Although it sounds like you're exercising a lot, you should make sure to add interval training and speed work to your running routine to add an extra calorie burn. Your muscles might also have hit a plateau with your strength training program. You want to mix up your strength training routine every six weeks to two months, and if you're not working your muscles to exhaustion you need to increase the amount of your weights. Make sure you're eating a well-balanced diet to support your running. Here is more advice for pushing past your weight loss plateau.

Also, it is common to have fluctuations in your weight from day to day, and even week to week.

Good luck on your half marathon!


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